I do agree that Sprague is actually a terrible policy for the resettling of displaced people. Many of the rumors offered by citizens on the planet, which you can freely read from the bar, are distinctly negative, with some being quite drastic. BMM's moral duplicity aside, it would make more sense if refugees were amassed on the midpoint of planet Cambridge, much to the chagrin of the local aristocrats. I suggest Cambridge because Cambridge is the closest colony to both Sprague and Canaria, but Canaria is presently not an option for mass resettlement because of the lack of gate/lane infrastructure at the moment.
Throwing 3 billion people onto Sprague is just asking for a full-scale revolt, especially with BMM putting the residential sites near active volcanic sites, or not properly sealing the subterranean habitats, resulting in flooding, this and the blackouts would quickly urge 3 billion people to become 3 billion dissidents. Giving them temporary accommodations on Cambridge and then filtering the refugees to either of the two resettlement sites, when possible, is more rational and effective than the current approach which seems more akin to "dumping" rather than resettling.
On indefinite hiatus because the current state of gameplay sucks - ping me over discord if replies are needed